Mexican Marine Reserve Sees Huge Jump in Fish

A new study revealed that undersea life at the Cabo Pulmo National Park of Mexico rebounded by more than 460 percent over 10 years after imposing a 15-year ban on fishing and other extractive activities.

Researchers at the Scripps Institution of Oceanography at the University of California, San Diego, conducted a study from 1999 to 2009. They recently published their findings in the journal Public Library of Science (PLoS) ONE.

They found that biomass, or the total amount of fish in the reserve ecosystem, boomed over 460 percent in the decade.

Cabo Pulmo was once depleted by fishing, but in 1995, citizens living around the area enforced "no take" restrictions that have resulted in the park's thriving. After four years, when researchers checked the marine park, they didn’t find many fish, except of few of medium size.

Researchers again dove in the water Cabo Pulmo National Park in 2009 to monitor the fish population. They were surprised to see that the fish biomass at the park had increased to 463 percent and the biomass of top predators and carnivores increased by 11 and 4 times, respectively.

Researchers found thousands of large fishes, such as snappers, groupers, trevally, manta rays, and even sharks. However, fish biomass in other marine protected areas or open access areas did not change significantly over the same period. Researchers say no other reserve in the world has shown such a recovery.

Protection of spawning areas for large predators has been the key to the reserve's robustness. But most importantly, local enforcement, led by determined families, has been a major factor in the park's success, the researchers noted.

“The most striking result of the paper…is that fish communities at a depleted site can recover up to a level comparable to remote, pristine sites that have never been fished by humans,” especially in a large area like Cabo Pulmo, researchers stated in the journal.

The 71-square-kilometer undersea park, which is tucked away near the southern tip of Mexico's Baja peninsula, is now the most robust marine reserve in the world.

The scientists pointed to the success of the Cabo Pulmo National Park as a strong example that depleted fisheries can recover up to a level that is comparable to remote, pristine sites untouched by fishing.